The powerful veterans group says lack of support puts pioneering, federally approved study in jeopardy.

The American Legion is calling on the U.S. Department of Veterans Affairs to clear roadblocks threatening completion of a groundbreaking clinical study on the use of medical marijuana to treat post-traumatic stress disorder (PTSD) in U.S. military veterans.

The federally-approved study is being administrated by Dr. Sue Sisley, site principal investigator with the Multidisciplinary Association for Psychedelic Studies (MAPS), at the Scottsdale Institute outside of Phoenix, Arizona.

The project is one of nine medical marijuana studies funded by historic grants from Colorado’s Health Department.